JP2724794B2 - Sliding surface structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding surface constituting a sliding surface with a mating member.

[0002]

2. Description of the Related Art Conventionally, as this kind of sliding surface structure, for example, in a piston for an internal combustion engine, an Fe alloy provided on an outer peripheral surface of a land portion and a skirt portion of a base material made of an Al alloy in order to improve wear resistance. Plating layers are known.

[0003]

However, under the current situation in which the internal combustion engine tends to operate at high speed and high output, the conventional sliding surface structure does not have sufficient oil retention, that is, oil retention. There is also a problem that the seizure resistance is poor due to poor initial conformability.

[0004] In view of the above, the present invention provides a sliding surface structure having a sufficient oil retaining property and good initial conformability by specifying a crystal structure, thereby improving seizure resistance. The purpose is to provide.

[0005]

The sliding surface structure according to the present invention comprises an aggregate of metal crystals having a body-centered cubic structure, and the aggregate slides on the (h00) plane with a Miller index. toward the surface side (h00) saw including at least one of the at oriented metal crystals and Miller indices of (3hh0) plane toward the sliding surface (3hh0) oriented metal crystals, the (h00) distribution
When the abundance ratio S _h00 of the directional metal crystal is 0% <S _h00 <25%
And the abundance S _{3hh0 of the} (3hh0) oriented metal crystal.
Is 0% <S _3hh0 <25% .

[0006] In this case, the existence ratio S _h00 and _S 3hh0,
That is, Sm (m is a Miller index such as hhh, 3hh0,
The same applies hereinafter). The sliding surface structure is bcc structure
X is composed of an aggregate of metal crystals
X-ray rotation with the irradiation direction set to the direction perpendicular to the sliding surface 4a
When the fold is performed, (hh0)
(Hh0) oriented metal crystal with its surface facing the sliding surface 4a side,
(H00) orientation with the (h00) plane facing the sliding surface 4a
Metal crystal, (2hhh) face (2)
hhh) Oriented metal crystal, (3hh0) plane as sliding surface 4a
(3hh0) oriented metal crystal and (hh
h) (hhh) Oriented metal with its surface facing the sliding surface 4a
The X-ray reflection intensity by the crystal appears.

In this case, the measurement sensitivity of each crystal plane is different.
In order to correct those measurement sensitivities to the same sensitivity level,
The measurement value Im of the X-ray reflection intensity in the oriented metal crystal is
In the ASTM card, the X-ray reflection intensity of the corresponding crystal plane
Divided by the degree ratio IAm, whereby the correction value Im / IAm
can get.

Further , the X-ray countermeasure by all the oriented metal crystals
The sum of the measured intensities is expressed as the sum T of the correction values.
It is.

Therefore, in the present invention, a kind of orientation
The abundance Sm (%) of the crystalline metal is defined as Sm = {(Im / IAm) / T} × 100 .

Therefore, (hh0), (h00),
(2hhh), (3hh0) and (hhh) oriented gold
The abundance of genus crystals is expressed as follows. (Hh0) Oriented metal crystal: S _hh0 = ｛(I _hh0 / IA
_hh0 ) / T｝ × 100, ( _h00 ) oriented metal crystal: S _h00 = ｛(I _h00 / IA)
_h00 ) / T｝ × 100, (2hhh) oriented metal crystal: S _2hhh = ｛(I _2hhh / I
A _2hhh ) / T｝ × 100, (3hh0) oriented metal crystal: S _3hh0 = ｛(I _3hh / I
A _3hh ) / T｝ × 100, (hhh) oriented metal crystal: S _hhh = ｛(I _hhh / IA)
_hhh) / T} × 100 _{Here, I hh0, I h00, I} 2hhh, I 3hh0, I hhh each
It is a measured value of the X-ray reflection intensity of the crystal plane. Also, IA _hh0 ,
_{IA h00, IA 2hhh, IA 3hh0} , IA hhh is ASTM mosquitoes
X-ray reflection intensity ratio of each crystal plane in the
_{hh0 = 100, IA h00 = 20} , IA 2hhh = 30, IA
_3hh0 = 12, it is the IA _hhh = 6. Further, T is T =
_{(I hh0 / IA hh0) +} (I h00 / IA h00) + (I
_{2hhh / IA 2hhh) + (I} 3hh0 / IA 3hh0) + (I hhh /
IA _hhh ).

[0011]

In the aggregate of metal crystals having a body-centered cubic structure, the (h00) plane is directed to the sliding surface side by the Miller index.
(00) Oriented metal crystals and / or Miller indices of (3)
hh0) toward the surface on the sliding surface side (3Hh0) when oriented metal crystals is present in the existence ratio S _h00, S _3hh0, the sliding surface, for example, a relatively large pyramidal (or truncated pyramid)
A large number of metal crystals are crystallized, and they have a state of interpenetrating. As a result, the sliding surface is composed of a number of fine peaks, a number of fine valleys formed between the peaks, and a number of fine valleys due to the penetration of the peaks. Because of the assembled appearance, the oil retaining property of the sliding surface structure is improved. Further, the preferential wear of the pyramid-shaped metal crystal on the tip portion side also provides good initial conformability of the sliding surface structure. However, the existence rate S _{h00 of} the (h00) oriented metal crystal is S
_{If h00} ≧ 25% or the abundance S _{3hh0 of} (3hh0) -oriented metal crystals is S _3hh0 ≧ 25%, the appearance of the sliding surface tends to be simplified with the increase of the oriented metal crystals. Therefore, the oil retaining property and initial conformability of the sliding surface structure are reduced.

[0012]

1 and 2 show a piston 1 for an internal combustion engine.
Has a base material 2 made of an Al alloy, and a land portion 3 _{1 of the} base material 2.
And the skirt portion 3 ₂ outer circumferential surface, a layered slide surface construction 4 is formed by plating.

As shown in FIG. 3, the sliding surface structure 4 is composed of an aggregate of metal crystals having a body-centered cubic structure (bcc structure). The aggregate faces the (h00) plane with the Miller index toward the sliding surface 4a with the cylinder bore inner wall 5, and the abundance S _h00 is 0% <S _h00 <25% (h00).
Oriented metal crystals and / or Miller indices (3 hh
0) The surface faces the sliding surface 4a side, and the existence ratio S _3hh0 is 0%.
<S _3hh0 <25% (3hh0) containing oriented metal crystals.

For example, if the bi-oriented metal crystal has the abundance S
_h00, when present at S _3Hh0, 4, as shown in FIG. 5, the sliding surface 4a, a relatively large pyramid or truncated pyramid, out numerous crystal is trigonal pyramid-shaped metal crystals 6 in the illustrated embodiment, They exhibit interpenetrated states. As a result, the sliding surface 4a is formed of a large number of fine peaks 7, a large number of fine valleys 8 between the peaks 7, and a large number of fine valleys 9 formed by mutual penetration of the peaks 7. Because of the assembled appearance, the oil retaining property of the sliding surface structure 4 is improved. In addition, since the tip of the triangular pyramid-shaped metal crystal 6 is worn preferentially, the initial conformability of the sliding surface structure 4 is also improved.

As shown in FIG. 6, the inclination of the (h00) plane with respect to the virtual plane 10 along the sliding surface 4a appears as the inclination of the triangular pyramid-shaped metal crystal 6, so that the oil retaining property of the sliding surface structure 4 And the initial conformability. Then, (h0
0) The inclination angle θ between the plane and the virtual plane 10 is 0 ° ≦ θ ≦
It is set to 15 °. The inclination angle θ is also 0 ° ≦ θ ≦ 15 ° for the (3hh0) plane. in this case,
The inclination direction of the (h00) plane and the (3hh0) plane is not limited. When the inclination angle θ is θ> 15 ° with respect to the (h00) plane and the (3hh0) plane, the oil retaining property and the initial conformability of the sliding surface structure 4 decrease.

As the metal crystal having the bcc structure, F
e, Cr, Mo, W, Ta, Zr, Nb, V, etc., or a crystal of a simple substance or alloy.

In the plating process for forming the sliding surface structure 4 according to the present invention, the basic conditions for performing the electric Fe plating process are as shown in Tables 1 and 2.

[0018]

[Table 1]

As organic additives, urea, saccharin and the like are used.

[0020]

[Table 2]

In the electric Fe plating process performed under the above-mentioned conditions, the (h00) and (3hh0) orientation F are determined depending on the cathode current density, the plating bath pH, and the amount of the organic additive.
The crystallization of the e crystal, its abundance, etc. are controlled.

[0022] As the plating process, the outside of the electroplating treatment include P VD method is an example Ebakisho plating method, CVD method, sputtering method, ion plating or the like. Conditions for performing W and Mo plating by the sputtering method are, for example, an Ar pressure of 0.8 Pa, an Ar acceleration power of 1 VDC, and a base material temperature of 100 ° C. W by CVD method
The conditions for plating are, for example, raw material WF ₆ , gas flow rate 10 cc / min, chamber pressure 100 Pa, and base material temperature 500 ° C.

Hereinafter, specific examples will be described.

[0024] Al land portion of alloy base material 2 3 ₁ and the skirt portion 3 ₂ outer circumferential surface, electrical Fe plating the slide surface construction 4 which is composed of an aggregate of Fe crystals by subjecting
To produce a plurality of pistons 1 for an internal combustion engine.

Tables 3 to 6 show Examples 1 to 1 of the sliding surface structure 4.
7 shows the conditions for the electric Fe plating process in Example 7. Tables 3 and 5 show the plating bath compositions, and Tables 4 and 6 show the processing conditions.

[0026]

[Table 3]

[0027]

[Table 4]

[0028]

[Table 5]

[0029]

[Table 6]

Tables 7 and 8 show the crystal morphology of the sliding surface 4a, the grain size of the Fe crystal, the abundance Sm and the hardness of each oriented Fe crystal in Examples 1 to 17, respectively.

[0031]

[Table 7]

[0032]

[Table 8]

The abundance Sm is obtained from the following equation based on the X-ray diffraction diagrams of Examples 1 to 17 (the X-ray irradiation direction is a direction perpendicular to the sliding surface 4a) . {110} oriented Fe crystal: S ₁₁₀ = {(I ₁₁₀ / IA)
₁₁₀ ) / T} × 100, {200} oriented Fe crystal: S ₂₀₀ = {(I ₂₀₀ / IA)
₂₀₀ ) / T} × 100, {211} oriented Fe crystal: S ₂₁₁ = {(I ₂₁₁ / IA)
₂₁₁ ) / T} × 100, {310} oriented Fe crystal: S ₃₁₀ = {(I ₃₁₀ / IA)
₃₁₀ ) / T} × 100, {222} oriented Fe crystal: S ₂₂₂ = {(I ₂₂₂ / IA)
₂₂₂ ) / T｝ × 100 where I ₁₁₀ , I ₂₀₀ , I ₂₁₁ , I ₃₁₀ , and I ₂₂₂ are the measured values (cps) of the X-ray reflection intensity of each crystal plane, and IA ₁₁₀ , IA ₂₀₀ , and IA ₂₁₁ , IA ₃₁₀ and IA ₂₂₂ are the X-ray reflection intensity ratios of each crystal plane in the ASTM card,
IA ₁₁₀ = 100, IA ₂₀₀ = 20, IA ₂₁₁ = 30,
IA ₃₁₀ = 12 and IA ₂₂₂ = 6. Further, T is T
_{= (I 110 / IA 110)} + (I 200 / IA 200) + (I
_{211 / IA 211) + (I} 310 / IA 310) + (I 222 /
IA ₂₂₂ ).

[0034]FIG. 7 is an X-ray diffraction diagram of Example 2.FIG.
Is a micrograph showing the crystal structure of the sliding surface 4a in Example 2.
True (5000 times). In FIG. 8,
Many triangular pyramidal Fe crystals are observed. Table 7 and FIG.
As shown, the (h00) oriented Fe crystals in Example 2
Therefore, the abundance of {200} oriented Fe crystalsS
₂₀₀ IsS ₂₀₀ = 1.2%, and (3hh0)
Of directional Fe crystals and thus {310} oriented Fe crystals
PresenceS ₃₁₀ IsS ₃₁₀ = 2.2%.

FIG. 9 is an X-ray diffraction diagram of Example 4, and FIG.
Is a micrograph (5000 times) showing the crystal structure of the sliding surface 4a in Example 4. In FIG. 10, a large number of relatively large triangular pyramidal Fe crystals and a large number of small pyramidal Fe crystals are observed. From FIG. 10, it can be seen that an oil reservoir is formed between the trigonal pyramid-shaped Fe crystals, and an oil reservoir is also formed by the small pyramid-shaped Fe crystals that are crystallized in a very complicated state between the valleys. . As shown in Table 7 and FIG. 9, the abundance S of the {200} oriented Fe crystal in Example 4
₂₀₀ is S ₂₀₀ = 3.3%, and the abundance S ₃₁₀ of {310} oriented Fe crystals is S ₃₁₀ = 5.4%.

FIG. 11 is a photomicrograph (5000 times) showing the crystal structure of the sliding surface 4a in Example 17. FIG.
Thus, the existence rate S _{310 of} the {310} oriented Fe crystal is S
It can be seen that when ₃₁₀ ≧ 25%, the appearance of the sliding surface 4a is simplified and becomes smooth.

Next, for Examples 1 to 17, a seizure test was performed by a chip-on-disk method, and the seizure load was determined. The results shown in Tables 9 and 10 were obtained. The test conditions are as follows. Disc material: Al-10% by weight Si alloy, disc rotation speed: 15 m / sec, oil supply: 0.3 ml / min, area of the sliding surface of the chip manufactured from the sliding surface structure 1 cm ² .

[0038]

[Table 9]

[0039]

[Table 10]

FIG. 12 shows {200} in Examples 1 to 17.
The relationship between the abundance S ₂₀₀ of the oriented Fe crystal and the seizure load is shown, and a line x ₁ indicates the abundance of the {310} oriented Fe crystal.
When S ₃₁₀ is S ₃₁₀ <25%, the line x ₂ is ｛31
The existence ratio S _{310 of the} 0 ° -oriented Fe crystal is S = 25 for S _310.
%, Respectively. As is clear from FIG. 12 and Examples 1 to 9, the abundance S of {200} -oriented Fe crystals
_By setting ₂₀₀ to S ₂₀₀ <25% and the abundance S ₃₁₀ of {310} -oriented Fe crystals to S ₃₁₀ <25%, the seizure load is increased to 550N or more to improve seizure resistance. Can be improved. However, Example 1
As in 3, prevalence S ₂₀₀ of {200} oriented Fe crystals
Is S ₂₀₀ = 0%, and when the abundance S _{310 of} {310} oriented Fe crystals is S ₃₁₀ = 0%, the seizure load is low.

[0041] Table 11, Table 12, the slide sliding surface construction 4, the abundance ratio S ₃₁₀ of {310} oriented Fe crystal S ₃₁₀
= 0% prevalence S ₂₀₀ of Example 18 and {200} oriented Fe crystals is set to indicate the electroplating process conditions in Example 1-9 was set at S ₂₀₀ = 0%.

[0042]

[Table 11]

[0043]

[Table 12]

Table 13 shows that the sliding surfaces 4 in Examples 18 and 19 are as follows.
The crystal form of a, the grain size of the Fe crystal, the abundance Sm of each oriented Fe crystal, and the hardness are shown.

[0045]

[Table 13]

When a seizure test was performed on the Examples 18 and 19 by the chip-on-disk method under the same conditions as described above, Examples 18 and 19 each had a seizure load of 940 N and {200} orientation. Fe crystal and ｛31
It was found that even if one of the 0 ° -oriented Fe crystals was not present, the sliding surface structure 4 had excellent seizure resistance.

The sliding surface structure is applied to, for example, the following sliding parts of internal combustion engine parts and the like. Piston (ring groove), piston ring, piston pin, connecting rod, crankshaft, bearing metal, oil pump rotor, oil pump rotor housing, camshaft, spring (end face), spring seat, spring retainer,
Cotta, rocker arm, roller bearing outer case, roller bearing inner case, valve stem, valve face, hydraulic tappet, water pump rotor shaft, pulley, gear, transmission shaft, clutch plate, washer, bolt (seat surface, screw).

[0048]

According to the present invention, by specifying the crystal structure as described above, it is possible to provide a sliding surface structure having excellent seizure resistance.

[Brief description of the drawings]

FIG. 1 is a side view of a piston.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a perspective view showing a body-centered cubic structure and its (h00) plane and (3hh0) plane.

FIG. 4 is a perspective view of a main part showing an example of a sliding surface structure.

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is an explanatory diagram showing an inclination of a (h00) plane in a body-centered cubic structure.

FIG. 7 is an X-ray diffraction diagram of an example of a sliding surface structure.

FIG. 8 is a micrograph showing a crystal structure of a sliding surface in an example of a sliding surface structure.

FIG. 9 is an X-ray diffraction diagram of another example of the sliding surface structure.

FIG. 10 is a micrograph showing a crystal structure of a sliding surface in another example of the sliding surface structure.

FIG. 11 is a micrograph showing a crystal structure of a sliding surface in another example of the sliding surface structure.

FIG. 12 is a graph showing the relationship between the abundance of {200} oriented Fe crystals and the load at which seizure occurs.

[Explanation of symbols]

 4 Sliding surface structure 4a Sliding surface

Claims (1)

(57) [Claims] The present invention comprises an aggregate of metal crystals having a body-centered cubic structure, wherein the aggregate has an (h00) oriented metal crystal with a (h00) plane directed toward a sliding surface with a Miller index, and a Miller index. in (3hh0) plane toward the sliding surface (3HH
0) only contains at least one of the oriented metal crystal, the (h
00) The existence rate S _h00 of the oriented metal crystal is 0% <S _h00 <
25%, and the presence of the (3hh0) oriented metal crystal
A sliding surface structure, wherein the ratio S _3hh0 is 0% <S _3hh0 <25% .